Blood tests for children and infants are done on the finger because the peripheral blood vessels in the forearms of children are very thin and usually cannot be found, and even if they are found, it is difficult to stick a needle in them. Therefore, if a child wants to have blood drawn or to check the blood routine, the finger is usually used. You can use the abdomen of the finger, and after sticking the finger, gently squeeze it with your hand, and you can squeeze out some blood to do routine blood tests. In adults, the peripheral veins of the forearm, usually located in the middle of the elbow, are used for routine blood tests. The peripheral vein is usually located at the middle of the elbow. After sterilizing the peripheral vein, the blood is drawn for routine blood tests. In general, there is not much difference between the blood tests for peripheral blood and venous blood from the finger prick.